Electron discharge device



Oct. 9, 1945. J. JoNAs ELECTRON DISCHARGE DEVICE Filed March 9, 1943 @M @my Entorno Patented Oct. 9, 1945 1 SwitzerlanrLa joint-stock ,company y y Application Marchio, 1943, serial No'. 478,532

i y In Switzerland January 26, 1942 -jvoliins' goreng-275) n It isa-known that in electronvdischarge devices where the current is conductedl through aygas or` Vvapour the arc can be prematurely yextinguished byvmeans of so-called .extinguishing-.grids at any instant during the time it is burning.;

U. S. A. PatentNo. 2,097,490. When the arc in a discharge device is, however, extinguished by means of such grids certain undesirable phenomena occur because the extinguishing process only takes an extremely short time, namely about 10-7 seconds. With higher currents this method of extinguishing the arc causes high excess voltages and in order to prevent the occurrence of these voltages it is necessary to connect large capacities parallel to the arc path. These capactities are of a considerable size and are not entirely adequate, however, when the discharge device is used to interrupt a circuit because the stored-up energy in the circuit is not dissipated.

The present invention concerns a single or polyphase electron discharge device with gas or vapour discharge path and several anodes per phase, the aforementioned disadvantages being avoided according to the invention by connecting the anodes of each phase in series over a resistance, the current being supplied to the rst anode of the series, and .by each anode having a device associated with it which is controllable and inuences the resistance of the arc path.

Two constructional examples of the invention are illustrated diagrammatically in Figs. 1 and 2 of the accompanying drawing.

The discharge tube a shown in Fig. 1 contains the anodes b1, b2, b3, b4, b5 which are connected together in series over the ohmic resistances c1 to c4, and. the mercury cathode d. At least the anodes b2 to b5 are constructed as ring anodes and are located in the path of the arc from the anode b1 which forms the rst of the series and -to which current is supplied. In front of each anode b1 to b5 is an extinguishing grid e1 to es respectively of the kind already mentioned and to which a negative blocking voltage from the voltage source f is applied. Switches g1 to g5 which are actuated one after the other are arranged in the leads to the extinguishing grids.

In order to extinguish the arc which normally burns between anode b1 and cathode d rst of all the arc path of the first anode b1 is blocked by means of grid e1 `by applying to this latter the blocking potential from the grid voltage source f by closing switch g1. The current then flows through resistance c1 and the arc then burns from the next anode b2. By blocking the arc path of the subsequent anodes b2, b3 and b4 with theentinguishing grids e2, es; and erfrespectively by closing` the correspondingswitches g2, g3 and g4 one after the..o.ther,.the,arc finally-reaches ,the last anode-zbt jofthe series..-` The:,operating current flowingover the resistances clito c4 isthus damped to `such `adeg-Vree;.that undesirable excess voltages no longer occur when the arc burning between the anode bs and cathode d is extinguished.

The arrangement described can be modied so that the current flowing through the resistance joining two anodes controls a device associated with one of the following anodes in order to iniiuence the resistance of its arc path.

The constructional example in Fig. 2 shows devices which supply the control currents successively to the means employed for control purposes in such a manner that first of Aall the arc path of the first anode and then one after the other the arc paths of the following anodes are blocked. The extinguishing grid e1 located in front of the rst anode b1 isv thus merelyy connected to the bias voltage f by closing switch g. The extinguishing grids of the subsequent anodes b2 to b5 are, however, controlled by means of the current flowing over the resistances c1 to c4 connecting these anodes. For this purpose transformers h1 to h4 respectively are provided, the primary windings of which lie in the connections between the resistancesl and the anodes whilst the secondary windings are mutually connected in parallel and supply the extinguishing grids of the subsequent anodes. When the arc path of the rst anode b1 is blocked by the grid e1 after the switch g is closed, the operating current ows over resistance c1 and the working arc passes to the next anode b2. 'Ihe necessary blocking voltage for the extinguishing grid e2 is then produced in the secondary winding of transformer h1 whereby the arc path of anode b2 is blocked. The arc paths of the remaining anodes of the series are then successively blocked in an analogous manner.

The arrangement according to the invention is particularly sui-table for interrupting highvoltage direct current and in this case it is an advantage to locate a supplementary switching device, for instance a gas blast circuit breaker with multiple break, in series with the discharge device. Interruption is then achieved in such amanner that by means of the discharge device the operating current is reduced to a fraction of its initial value and the remaining residual current is then completely interrupted by the supplementary switching device.

each said device controlling arcing' conduction" to its associated anode in accordance with the potentials impressed upon that. device 2. An electron discharge device as recited in.

claim 1 wherein said resistance means comprises ohmic resistance connecting said" additional? an odes in series.

3. An electron discharge device as recited-in claim l, wherein the control device associated with tl'iev first anodey is a controllable arc-extinguishing grid between the first anode andthe adjacent. one of said additional anodes.

4. An electron dischargev device as recited: in claim l, wherein each` of sadcontrol devices is a'controllable arc-extinguishing grid.

5. An electron discharge device as recited in claim l, in combination with means responsive to current flowing in the resistance means between one of said additional anodes and said iirst anode to alter the energization of a control device that aiects arcing conduction to that said additional anode.

6i An electron discharge device? comprising an envelope, a, vaporizable cathode, a rst anode, a. plurality of additional anodes spaced along the arc path to said rst anode, resistances connectingy said additional anodes in series with each other.. and with said first anode, a control device for blocking conduction along the portion of the ardpath. Between. said iirst anode and the adjacent additional anode, and means responsive to such blocking for progressively blocking conduction along portions of the arc path between adjacentv additional anodes.

7. An electron discharge device as recited in claim 6; wherein said last means comprises a control device for each of said additional anodes, anda transformer coupling between each addi'- tional anode and its associated control device.

JULIUS Jointsi 

